Medicament container holder arrangement

TECHNICAL AREA

0001The present invention relates to a medicament container holder arrangement to be used in a medicament delivery device and in particular a medicament container holder arrangement that is capable of preventing containers e.g. cartridges, syringes or the like from breaking during medicament delivery.

TECHNICAL BACKGROUND

0002There are a number of medicament delivery devices on the market in which a medicament container is placed, usually in an appropriate container holder designed to accommodate a certain type and size of the medicament container.

0003Further, there are a number of different medicament containers on the market, such as the common syringe type having laterally extending flanges at the distal part thereof, which flanges act as stop members against longitudinal movement, and cartridges having a proximal neck portion, onto which a needle may be attached, which cartridges normally are supported against a shoulder surrounding said neck portion. Almost all of the syringes and cartridges on the market are manufactured from glass, being a very suitable material that will not react with the medicament, does not age and can readily be sterilized.

0004Lately a new type of needle shield has been developed, which is commonly called Rigid Needle Shield or RNS. The RNS comprises a cap which has a hard, semi-transparent plastic shell, with a soft and flexible inner core which protects a syringe needle. The soft core is made of thermoplastic elastomer (TPE), into which the needle sticks to protect it from damage whilst also providing a sterile seal.

0005The cap has very often generally the same diameter as the cartridge onto which it is connected; thereby the cartridge has to be provided with flange members at the distal part of the container. It is not uncommon that glass medicament containers break during e.g. an injection process due to the high forces that are produced from medicament delivery force members, such as injection springs, acting on plunger rods, which in turn are intended to push stoppers inside the medicament containers for expelling medicament.

0006Other possible causes where the medicament containers may break are during a penetration process. It is of course also possible that a medicament container may break if the medicament delivery device is dropped on a hard surface.

0007When using so called rigid needle shields, since they have generally substantially the same diameter as the medicament containers on which they are mounted, when placed in a medicament container holder, they are difficult to support at a proximal shoulder portion of the container.

0008This in turn means that if the medicament container breaks for some reason, pieces of the container will fall out through the proximal opening of the device because there is nothing in the proximal area that is holding the medicament container. There is thus a risk that persons may be injured by broken glass from the medicament container.

0009WO 2007/08115 discloses an autoinjector wherein a medicament container with a needle and a needle cover is placed in a container holder that supports the container at the front using flexible arms that grip the container in the gap between the needle cover and a shoulder portion of the container. The support is intended to prevent breakage or to stop broken pieces from falling out of the container holder. No support is provided at the rear flanges of the container.

0010However, experience has shown that it is not always enough to support a container or syringe only at the shoulder portion or at the rear flange in order to prevent it from breaking. Fluids of high viscosity necessitate stronger driving forces for ejecting medicament. Consequently the syringe or cartridge is subjected to greater forces, resulting in increased risk of breakage.

BRIEF DESCRIPTION OF THE INVENTION

0011A main aim of the present invention is to remedy the drawbacks associated with medicament containers provided with RNS.

0012This aim is obtained by the features of the independent patent claim. Preferable embodiments of the invention form the subject of the dependent patent claims. According to a main aspect of the invention it is characterised by a medicament container holder arrangement intended to be used in a medicament delivery device, comprising a medicament container holder and a medicament container wherein the medicament container holder is provided with distally arranged support surfaces for flanges arranged on a distal part of the medicament container to be placed in said medicament container holder, which medicament container is arranged with a needle shield to the proximal end thereof, wherein said needle shield has a diameter generally equal or larger than the diameter of said medicament container, characterised in that said medicament container holder arrangement further comprises holders arranged on the container holder for holding said medicament container around a proximal shoulder portion thereof and a resilient support element arranged between the flanges and the support surfaces whereby the holders and the resilient support element absorb and spread forces between the medicament container and the container holder.

0013According to another aspect of the invention said resilient support element is manufactured from a flexible material, such as TPE.

0014According to another aspect of the invention said resilient support member is in the form of a ring arranged around the medicament container, adjacently a proximal surface of the flanges.

0015According to another aspect of the invention said resilient support member is in the form of a cushioning element integrally attached to the support surfaces.

0016According to a further aspect of the invention said holders comprise flexible arms arranged such that, when a medicament container is placed in said medicament container holder from the distal end thereof and pushed forward such that said needle shield comes in contact with the flexible arms, the latter are capable of flexing outwardly, permitting passage of said needle shield, and then capable of flexing inwardly after passage of said needle shield.

0017According to yet another aspect of the invention said flexible arms are provided by through-going U-shaped slits on the longitudinal extending surface of the holder.

0018According to another aspect of the invention said flexible arms further comprise inwardly directed ledges capable of being placed in contact with said shoulder portion of said medicament container.

0019According to another aspect of the invention said holders further comprise outwardly directed ledges cooperating with a housing part of said medicament delivery device such that, when the container holder is positioned inside said housing part, said flexible members are prevented from flexing radially outwards, thereby firmly holding said medicament container.

0020There are a number of advantages with the present invention. The support surfaces, together with the support element, abut against the flanges of the container and the holders grip the container at the front. Together they divide the forces acting on the container during medicament delivery to prevent the container from breaking.

0021Due to the holders arranged on the medicament container holder, the medicament container, or parts of it, are prevented from moving further in the proximal direction should the distally arranged flanges no longer be able of holding the medicament container, due for example by breakage of the medicament container.

0022Because the holders preferably are radially flexible it is possible to pass the rigid needle shield of the medicament container when placing the latter in the medicament container holder. Since also the members preferably have inwardly directed ledges, a good hold of the neck portion of the medicament container is obtained.

0023These and other aspects of and advantages with the present invention will become apparent from the following detailed description and from the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

0024In the following detailed description of the invention, reference will be made to the accompanying drawings, of which

0025<figref idref="DRAWINGS">FIG. 1</figref> shows an exploded view of a proximal part of a medicament delivery device provided with a medicament container holder according to the present invention,

0026<figref idref="DRAWINGS">FIG. 2</figref> shows an exploded view of a distal part of the medicament delivery device of <figref idref="DRAWINGS">FIG. 1</figref>,

0027<figref idref="DRAWINGS">FIG. 3</figref> shows a detailed view of a medicament container holder according to the present invention,

0028<figref idref="DRAWINGS">FIG. 4</figref> front view of the holder of <figref idref="DRAWINGS">FIG. 3</figref>, and

0029<figref idref="DRAWINGS">FIG. 5</figref> shows a cross-sectional view taken along line V-V of <figref idref="DRAWINGS">FIG. 4</figref>.

DETAILED DESCRIPTION OF THE INVENTION

0030In the present application, when the term “distal part/end” is used, this refers to the part/end of the medicament delivery device, or the parts/ends of the members thereof, which under use of the medicament delivery device is located the furthest away from the medicament delivery site of the patient. Correspondingly, when the term “proximal part/end” is used, this refers to the part/end of the medicament delivery device, or the parts/ends of the members thereof, which under use of the medicament delivery device is located closest to the medicament delivery site of the patient.

0031The present invention relates to a medicament container holder arrangement comprising a medicament container holder <b>16</b> and a medicament container <b>18</b> wherein the medicament container holder <b>16</b> is provided with distally arranged support surfaces <b>25</b> for flanges <b>24</b> arranged on a distal part of the medicament container <b>18</b> to be placed in said medicament container holder <b>16</b>, which medicament container <b>18</b> is arranged with a needle shield <b>20</b> to the proximal end thereof, wherein said needle shield <b>20</b> has a diameter generally equal or larger than the diameter of said medicament container <b>18</b>, wherein said medicament container holder arrangement further comprises holders arranged on the container holder for holding said medicament container <b>18</b> around a proximal shoulder portion <b>22</b> thereof and a resilient support element <b>23</b> arranged between the flanges <b>24</b> and the support surfaces <b>25</b> whereby the holders and the resilient support element <b>23</b> absorb and spread forces between the medicament container and the container holder.

0032A medicament delivery device <b>8</b> comprising the present invention comprises a generally tubular outer housing <b>10</b>. In the proximal end of the housing, to the right in <figref idref="DRAWINGS">FIG. 1</figref>, a generally tubular needle shield <b>12</b> is arranged slidably in the outer housing. When in a non-extended position the needle shield is held in place by protrusions <b>14</b> on the outer surface co-operating with ledges (not shown) on an inner surface of the housing <b>10</b>. Inside the needle shield in the proximal area of the device, the medicament container holder <b>16</b> is arranged, which will be described in more detail below. Inside the medicament container holder <b>16</b> the medicament container <b>18</b>, containing medicament, is arranged. The medicament container is provided with a so called rigid needle shield RNS <b>20</b> attached to a proximal neck portion of the medicament container <b>18</b>, which neck portion transforms into a shoulder portion <b>22</b>. The needle shield <b>20</b> has a diameter generally equal or larger than the diameter of said medicament container <b>18</b>. The distal end of the medicament container is provided with outwardly directed flanges <b>24</b>. Since the flanges are usually not designed to withstand large loads, the resilient support element <b>23</b>, made of a flexible material such as TPE, is arranged between a proximal surface of the flanges <b>24</b> and a support surface <b>25</b> of at the distal end of the container holder <b>16</b>, for absorbing and spreading forces between the flanges <b>24</b> and the support surfaces <b>25</b>. The resilient support element <b>23</b> may be in the form of a collar arranged adjacently a proximal surface of the flanges <b>24</b>. Alternatively it may be in the form of a cushioning element integrally attached to the support surfaces <b>25</b>.

0033A generally elongated plunger rod <b>30</b> extends into the medicament container <b>18</b> with one end adjacent a stopper positioned inside the medicament container. The distal end of the plunger rod <b>30</b> is surrounded by an activation housing <b>34</b> which is snap-fitted to the medicament container holder <b>16</b> through a holder <b>26</b> which is a part of the activation housing. The activation housing <b>34</b> is arranged with flexible tongues <b>36</b>, where each tongue is arranged with inwardly directed ledges. In an initial state, these ledges are positioned in a circumferential groove <b>38</b> on the plunger rod <b>30</b>. The tongues and ledges are held in this position by an injection release ring <b>28</b>. Inside the plunger rod, an injection spring <b>88</b> is arranged compressed between a proximal wall of the plunger <b>30</b> and a distal wall part of the activation housing <b>34</b>. The activation housing is further arranged with outwardly extending protrusions arranged on flexible arms <b>44</b>. Abutting the outwardly extending protrusions is a retraction release ring <b>46</b>. A spring <b>48</b>, hereafter named penetration spring, is arranged between the retraction release ring <b>46</b> and a penetration sleeve <b>50</b>. At the proximal end of the penetration sleeve <b>50</b>, a retraction spring retainer <b>52</b> is snap fitted with the penetration sleeve <b>50</b> by outwardly directed protrusions <b>54</b> having a straight part and a ramped part, extending into recesses <b>56</b> of the sleeve. Outside the penetration sleeve a lockout sleeve <b>58</b> is coaxially arranged. At the rear part of the lockout sleeve <b>58</b> recesses <b>60</b> are arranged adjacent flexible arms <b>62</b> of the penetration sleeve, which arms are arranged with outwardly extending protrusions as well as inwardly extending ledges. In the initial position these ledges are in contact with a circumferential groove <b>68</b> on the activation housing. The upper part of the arms <b>62</b> is further arranged with inclined surfaces. At the upper end of the housing <b>10</b> an activation button <b>72</b> is slidably arranged, having axial extending parts <b>74</b>, which are arranged with inclined surfaces facing the inclined surfaces of the arms <b>62</b>.

0034The medicament container holder <b>16</b> has a tubular shape comprising a circumferential and longitudinal extending surface provided with a number of holders which are axially extending flexible arms <b>80</b> arranged in the material of the holder. U-shaped through-going slits <b>82</b> are made on the longitudinal extending surface of the holder <b>16</b> such that the arms <b>80</b> are directed in the proximal direction. The ends of the flexible arms <b>80</b> are arranged with generally radially inwardly directed ledges <b>84</b> that are intended to cooperate with the neck of the medicament container. Further the ends of the arms <b>80</b> are also provided with radially outwardly directed ledges <b>86</b>.

0035In use, when a medicament container <b>18</b> is to be placed in the medicament container holder <b>16</b>, the resilient support element <b>23</b> is arranged on the container abutting the flanges and the container is pushed into the container holder <b>16</b> from the distal end and towards the proximal end of the medicament container holder <b>16</b>. Alternatively, the cushioning element is integrally attached to the support surfaces <b>25</b> and the container is pushed into the container holder <b>16</b> from the distal end and towards the proximal end of the medicament container holder <b>16</b>.

0036When the rigid needle shield <b>20</b> at the proximal end of the medicament container comes in contact with the inwardly directed ledges <b>84</b> of the flexible arms <b>80</b>, the latter will flex outwards in the radial direction, thereby allowing the rigid needle shield <b>20</b> to pass the ledges <b>84</b>. The ledges <b>84</b> will then flex back inwardly when the rigid needle shield has passed the ledges, after which the ledges come in contact with the shoulder portion of the medicament container. Further, the flanges <b>24</b> of the medicament container are now, via the resilient support element <b>23</b>, in contact with the support surface <b>25</b> of the distal part of the medicament container holder. Said outwardly directed ledges <b>86</b> are arranged to cooperate with a housing part of said medicament delivery device when the container holder is positioned inside said housing part, such that said flexible members are prevented from flexing radially outwards, and thereby firmly holding said medicament container.

0037Should now a breakage of the glass medicament container occur during a medicament delivery process, such as an injection, due to the forces exerted by drive force means such as injection springs, the pieces of the medicament container are kept inside the medicament delivery device and do not fall out through the proximal opening of the device.

0038It is to be understood that the embodiments described above and shown in the drawings only are to be regarded as non-limiting examples of the invention and that it may be modified in many ways within the scope of the patent claims.